This invention relates to an abrasive article comprising abrasive agglomerate particles and a bond system.
Abrasive articles have been used to refine or abrade the outer surface of a workpiece. In some instances this refining process abrades large amounts of material, for example, in high pressure grinding for removing gates from metal castings. In other instances, this refining process generates extremely fine surface finishes as in the case of polishing such a metal casing. Thus, abrading processes can range anywhere from cutting to polishing.
There is generally one common thread amongst all types of abrasive articles and abrading processes. This common thread is the inverse relationship between cut rates and surface finish. The ideal abrasive article will provide high cut rates (i.e., material removal rates) and will simultaneously generate a fine surface finish on the workpiece being abraded. Generally, however, abrasive articles that tend to generate high cut rates tend to also generate coarse surface finishes. Likewise, in general, abrasive articles that tend to generate finer surface finishes tend to also generate lower cut rates.
Typically, coated abrasives have either one or two layers of abrasive grains bonded to the backing and these abrasive grains are usually oriented to provide optimum cut rates. However, with only one or two layers of abrasive grains, the product life of a coated abrasive may not be as long as desired. In recent years, attempts have been made to increase the life of coated abrasives by bonding abrasive agglomerates to a backing. These abrasive agglomerates comprise a plurality of abrasive grains bonded together by a binder to form an agglomerate particle. These agglomerate particles are then bonded to the backing. Since these agglomerate particles are essentially three dimensional, they provide many "layers" of abrasive grains that can participate during grinding. In some instances, coated abrasives with agglomerate particles may provide longer life.